Characteristics and frequency distribution of bone defect configurations in peri-implantitis lesions-A series of 193...

Knowledge on peri-implantitis bone defect characteristics and predictors is still limited.

To describe peri-implantitis bone defect characteristics and identify possible predictors.

Various parameters at patient- (age, gender, smoking, and supra-structure), implant- (surface, type, connection, platform, and misfit), and site level (region, alveolar ridge position, defect characteristics, neighboring structure) were recorded retrospectively.

Among 193 implants, the most prevalent defects were class Ic (25.4%), and Id (23.8%); a previously non-described category "class Id with only one bone wall" was frequently observed (11.9%). Mean intrabony defect depth and width ranged from 4.5 to 6.2 mm and from 2.7 to 2.9 mm, respectively; mean dehiscence extent ranged from 2.8 to 7.0 mm. A total of 37.8% of the defects presented horizontal bone loss and an intrabony component; in 52.7% of the implants, total defect extent was >6 mm. Jaw region, implant position within the alveolar ridge, and implant/abutment misfit showed significant associations either to defect configuration and/or defect extent.

(a) Most common peri-implantitis defects exhibited a combination of intrabony component and a buccal/oral dehiscence, while purely circumferential defects were relatively seldom; (b) implants with defects with bone dehiscence were placed more frequently closer to the lateral aspect of the ridge harboring the dehiscence; (c) implants placed in the lower anterior region had the highest risk for more severe peri-implant bone loss; and (d) peri-implant bone defects with only a single bone wall appropriate for regenerative procedure were relatively frequent.